The antonym for bruteful could be...
angelic, calm, considerate, gentle, homedous, kind, meek, peaceful, pleasant, saintly or warmhearted
The best antonym for pessimism is optimism.
An antonym for the word 'worst' is 'best'.
worst
Worst
A possible, not necessarily the best antonym for conclave is disassemble. Hope this helps
Most.
harmless
professional
adjust
Celebrate
test
Manageable.